Llansannan is situated south of Abergele in the county of Conwy, North Wales. It is bordered by Llanfair Talheiarn to the north, Bryn Trillyn to the south, Llangernyw to the north west and Denbigh to the east. Nearby towns and villages include Rhuddlan, Rhyl, Bodelwyddan, St Asaph, Llanrwst, Betws yn Rhos, Llysfaen and Ruthin. The river Aled winds its way through the village before joining the river Elwy to the west of Llanefydd.

The village church was founded by St Sannan. There is a report that the building was in a dilapidated state in 1731 and it was either rebuilt or remodelled in 1777-8, the arcade with fluted timber piers. Llansannan church consists of a double nave and chancel, a west bellcote between the two nave gables, and a south porch about halfway along the south side of the nave.